Machine for delasting boots and shoes



Dec. l1, 1934. M. GRUNE 1,984,263

MACHINE FOR BELASTING BOOTS AND SHOES Filed4 Sept. 18, 1953 INVENTOR:

had tomechanical delasting, by meansof suitable Patented Dec. 11, 1934 UNITED STATES PATENT OFFICE Max Grune, Pirmasens, Germany, assigner to vSchn & Cie. A. G.,

` Pirmasens, Germany Application september 1s, 1933, serial No. 600,004

In Germany December 30, 1932 y 18 Claims.

This invention relates .to a machine for delasting boots and shoes. The delasting of blocked shoes, when performedby hand, is a very exhausting operation and, for this reason, recourse has been delasting machines'. The machines of this kind hitherto devised have not, however, been widelyr used, as they are by no means a perfect substitute for hand labour and, inv particular, have the disadvantage that the shoes are very easily damaged when being Idelasted. When these known delasting machines are used it is impossible to prevent the ldelasting tool from slipping on the uppers of the shoes mounted on the gripper last. The vfriction thus produced damages the surface of the leather, spoiling its appearance and mayk ed on the last against the `delasting mechanism` and also -for moving the delasting tool for the purpose of stripping the shoes from the last. It is preferable to use separate hydraulic pistons, the pressurecylinders of which `areat right angles to eachother, for pressing the shoe against the last and for vdelasting it, care being taken, by the provision of suitable vhydraulic passages or the like, that the pressure medium first moves the piston which presses the shoe against the last and only acts on the piston which produces the move` ment of the delasting tool after a denite pressure upon the shoe on the last has been attained.4

When hydraulic operating mechanism of this kind is employed it can be simply and satisfac-4 torily ensured that the shoe blockedon the last is pressed against the latter vbefore the delasting tool begins to move, with a pressure which, when the said tool begins to move, is powerful enough to render slipping of the tool on the upper of the shoe impossible.

The accompanying drawing shows, by way of example, a constructional form of machine according tothe invention.

In this drawing:

Fig. 1 is a vertical section through a hydraulically yoperated de-lasting machine.

Fig. 2 is a view of the upper portion of the f machine in another operative position and Fig. 3` is a section taken on the yline A-B in Fig. f1. i Y

In the hollow standard r1 ofthe machine and on va bracket 2 isvmounted a gear wheel pump 3 of the well known type of construction.' "Oil, or other suitable liquid, is drawn up from a sump 5 through the suction pipe 4 of this pump, which delivers it, through a force pipe 6, into a passage la in a cylinder block '7, containing the principal parts of the machine. f

In the upper part/ofthe block 7 is a vertical cylindrical bore in which works Aa piston 8, provided, at its upper end, with a cylindrical extension 8a, of smaller diameter, on which is mounted a sleeve v9 :provided with a collar 9a. On to the sleeve 9 'is pressed a delasting tool 10, made of a yielding material, preferably rubber, said delasting tool being substantially `cylindrical in shape. Against the upper end faceof the delasting tool ybears the outer edge oa disc 11, which is held in position lby a screw 12 screwed into the end face of the extension 8a.

Below the cylindrical bore containing the pis--4 ton 8 there is provided inthe block '7 a horizontal cylindrical bore in which a second piston 13 works. This piston 13 has two annular grooves 13a and 13b turned in it and has in its inner or rear portion an axial bore in which a ball valve is mounted. This valve consists of a ball 15, which is pressed 'by a piston 16 acted on by a spring 14 against a sleeve 17, which latter is con-4 structed to form a valve seat and is screwed into the rbore aforesaid in the piston 13. This bore, containing the ball valve, communicates through a passage 13y with the annular groove 13b. The right hand end of the same bore communicates through a vertical passage 7d with the bore 'Za in the block 7.'

To the left hand end of the piston 13 is xed a pin 18 about which engages the lower end of a klever 20 adapted to rock cna pin 19. This lever 20 carries, at its upper end, a pin 21, upon which can be mounted a gripper vlast 22 with the shoev 23 blocked thereon. To vthe lower arm of the lever 20 is attached a tension spring 24 which tends to hold the lever 20 and, with it, the piston 13 in the right hand terminal position shown in Fig. 1.

In the lower part of the block 7 is provided a vertical bore for the reception .of a reversing valve. This valve comprises a bushing 25, closed at its upper end and having within its bore, a safety valve comprising a valve seat 26, a. ball 27, a bored through sliding member 28 anda pressure spring 29. Thefupper end of the spring'29' bears against the underside of the sliding member 28 and at its lower end against an end piece 30 which is provided with a passage 30a and is screwed into the bore in the bush 25. The end piece 30 carries at its lower part a pin 3l, about which flts one end of a lever 35 adapted to rock on a pin 34. To the other end of the lever 35 is pivoted the upper end of a rod 33 the lower end of which is connected to one end of a pedal lever 32 adapted to rock on a pin 38. To the lever 32 is attached a tension spring 36 which tends to hold the reversing valve in the terminal position shown in Fig. 1.

The bushing 25 of the reversing valve has turned in its outer surface an annular groove 25a from which extends an axial recess 25b axially aligned with the point at which the passage 7a opens into the block 7. From the side of the reversing valve bore opposite to this recess there extends a passage 7b which opens into a passage 7's in the block 7. This passage 7c leads from the interior of the hollow standard l to the horizontal cylinder containing the piston 13.

The machine operates as follows:

In the position of rest (shown in Fig. l), in which the reversing valve 25 occupies its upper terminal position the oil delivered through the force pipe 6 and the passage 7a ows round the annular groove 25e turned in the reversing valve and then passes back, through the passages 7b and 7c, directly to the oil sump.

Before starting the machine the last 22, carrying the shoe 23 to be de-lasted, is set up on the pin 21 of the lever 20 and then the pedal lever 32 is depressed. This results in the reversing valve 25 being moved downwards until the upper edge of the groove 25a turned in it overlaps the lower edge of the passage 7b, whereby return of the oil through the passages 7b and 7c is out off. Consequently, the oil rises through the passage 7c1 into the cylinder containing the piston 13 and forces this latter towards the left, until the heel portion of the shoe 23 is brought to bear against the rubber delasting tool 10. When this movement of the piston 13 takes place the groove 13b turned therein is brought into communication with the cylinder containing the vertical piston 8, while communication of the groove 13a with this said cylinder is cut 01T. As the travel of the piston 13 is limited by contact of the shoe 23 with the last tool 10, the oil pressure continues to rise until the pressure of the spring 14 is overcome and the ball 15, carrying with it the piston 16, is lifted from the valve seat at the inner end of the sleeve 17. In this way communication is established between the two cylinders containing the horizontal piston 13 and the vertical piston 8, respectively. Oil then flows through the passage 13c and groove 13u into the vertical cylinder and causes the piston 8 and the de-lasting tool 10 to move upwards. When this movement of the lasting tool takes place the heel portion of the shoe 23 is moved upwards, in the manner shown in Fig. 2, to such an extent that a light pull with the hand in the direction of the toe end suffices to remove the shoe from the last. After the shoe has been de-lasted the operators foot is taken off the pedal 32, so that the reversing valve 25 can move back to the upper terminal position under the i'etractile force of the spring 36. When this takes place the groove 25a again registers with the passages 7@1 and 7C, so that the oil under pressure, which continues to be delivered through the pipe 6, can pass back, Without producing any effect, into the oil .Sump

5, while the oil on the right hand side of the piston 13 can also run back into the sump through the passage 7d.

The pressure acting on the piston 13 is thus relieved and this piston is therefore moved back into the right hand terminal position by the tension spring 24. By this return movement of the piston 13 the annular groove 13a is again brought into communication with the vertical cylinder containing the piston 8, so that the oil under pressure can also run back out of this cylinder, by way of said groove 132L and the passage 7a into the oil sump, leaving said piston 8 free to descend into its lowest position under its own weight or under the action of a spring or a counterweight. When the piston 13 moves back the lever 20 is, at the same time retracted into the position shown in Fig. 1, so that it is ready for the reception of a fresh last.

In order that a predetermined maximum pressure may not be exceeded while the machine is in operation, there is provided in the reversing valve 25 a passage 25, which connects the recess 25b with the internal bore of the valve. As soon as any unforeseenfexcess of pressure develops the oilpressure acting on the ball 27 overcomes the force of the spring 29 and the ball 27 is accord ingly raised from` its seat 26. The oil then runs through the bore or passage in said seat 26,

through another bore in a sliding member 28,

hollow standard 1 is connected to the cylinder in which this piston works. If the operator attending the machine neglects to take his foot off the pedal 32 at the proper time the piston 8 continues to move until its lower face reaches the level where the pipe 37 enters the cylinder and, as soon as this point is reached, the oil escapes into said pipe and flows therethrough back into the oil sump 5. Consequently, no further upward movement of the piston 8 can take place.

The de-lasting tool 10, preferably made of soft rubber, is provided, on its periphery, with a number of longitudinal flutes or channels 10a, the cross sectional form of which is adapted to the shape of the heel portion of the particular shoe to be delasted. Accordingly, by rotating the said tool, it can be brought into a position in which the maximum amount of surface contact is afforded between the shoe and the particular iiute or channel 10a thus selected. The specific pressure (pressure per unit area) on the leather is thus reduced to a minimum, so that the leather is protected from injury to the greatest possible extent. In some cases the flutes 1021 may be so shaped that they conform to the shape of the heel portion of the shoe not only in horizontal section but also in vertical section; in this way a still greater reduction in the specific surface pressure can be obtained.

The above described hydraulic mechanism for pressing the shoe to be delasted against the dclasting tool and for shifting the said tool affords the special advantage that, in a certain measure, the forces required for the de-lasting operation adjust themselves automatically according to the grip with which the shoe holds on to the last so that very satisfactory delasting of the shoe is effected. 1n the constructional arrangement oi the hydraulic mechanism care is taken that the pressure with which the shoe is pressed against the tool always bears a denite relationship to the lilll force required. for delast'ing This relationship or ratio which can easily be ascertained by practical testsr corresponds' to the ratior betweenv the efteotive piston surface of; the vertical piston 81 and that of the horizontal piston 13. A shoe which nts tightly on to the last will, accordingly, be subjected to a greater pressure than one which ts'less tightly, While, on the other hand the shoe will not be morey heavily pressed than is' just necessary for delasting. Slipping of the delasting. tool over the upper is prevented by the verticali movement of the tool beginning only when the necessary pressure against the last has been obtained.

1.V In a machine for cle-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said :frame and on which the shoe to be cle-lasted is mounted,

a de-lasting tool carried by said frame and movable relatively to said support and the lastcarried thereby, hydraulic means for pressing the last against the (ie-lasting tool, and hydraulic means for moving said tool relatively to said last for the purpose of' stripping the shoe from the last.

2. In a machine for de-lasting boots and shoes, in combination. with the machine frame, a support for a last movably arranged on said frame and on Whichthe shoe to be cle-lasted is mounted, a de-lasting toolI carried by saidframe and movable rela-tively to said last, two hydraulic pressure cylinders arranged at right angles to each other on said frame, andk hydraulic pistons Working in said cylinders, said pistons being connected Withsaid support and tool and adapted to press the last carried thereby against the tool and tomove said tool relatively to said last for the purpose of stripping the shoe from the last.

3. Ina mach-ine for cle-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de--lasted is mounted, a de-lasting tool carried by said frame andv movable relatively to said last, two hydraulic pressure cylinders arranged at right angles to each other onsaid frame, hydraulic pistons working in said cylinders, said pistons being connected with said support and tool and adapted to press the last carried thereby against the tool and to move said tool relatively to said last for the purpose ofstripping the shoe from thelast, and means adapted to hydraulically connect said cylinders with each other so that the piston, which presses thev support and the last carried thereby against the tool, is rst moved by the pressure medium, while movement of the piston connected to the de-lasting tool takes place only after a definite pressure has been attained.

4. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted, a delasting tool carried by said frame and movable .relatively to rsaid last, two hydraulic pressure cylinders arranged at right angles to each other on said frame, hydraulic pistons Working inv said cylinders, said pistons being connected with said support and tool and adapted to press the last carried by the support against the tool and to move said tool relatively to said last for the purpose of stripping the shoe from the last, and a supply pipe for the pressure medium communieating with the cylinder of the piston which presses'the lastagainst the tool and passages. provided on said supply pipe and. adapted, when said. piston moves, tofestablish communication between the two pressure cylinders.

5i. In a machine for de-lasting boots and shoes,l in combination withthe machine frame, a support for a last movably arranged on said frame and ony which the shoe to be de-lasted is mounted, a. de-

lasting tool carried: by said frame and movable relatively to: said; last, two hydraulic pressure cyl.- inders arranged at right angles. to each. other on said fram-e, hydraulic pistons Working. in said` cylinders, said pistons being connected with said support and tool and adapted to press thev lastl carried by the support against-the tool and toy move said tool relatively to said last for the purpose. of

stripping the shoe from the last, a supply pipe for the pressure medium communicating with the cylinder of the piston which presses the last against the tool, and a Valve located in said pipe' and being so loa-ded that it is adapted to establish communication vbetween the two pressure cylinders only after a predetermined pressure hasbeen the tool and to move said tool relatively to said last for the purpose of stripping the shoey from the last, the effective areas of the two pistonsbeing such that the pressure exerted pressingy against the last bears a definite and constant ratio to the force exerted on the shoe by' the movement' of the de-lasting tool.

7'. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support fora last movably arranged on said frame and on which the shoe to be d'e-lasted is mounted, a de-lasting tool. carried by said' frame and movable relatively to said last, two hydraulic pressure cylinders arranged at right angles to each other on said frame, hydraulic pistons Working in said cylinders, said pistons being connected with,v said support and tool and adapted to press the last carried by the support against the toolV and-,to

move said tool relatively to said last for the pur-v pose of stripping the shoe from the last, and a liquid pump common to both cylindersv and adaptedfto deliver the pressure medium to both cylinders. l

8. In a machine for de-lasting boots and shoes, in combination. with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted,

a cle-lasting tool carried by said frame and movable 'relatively to said last, two hydraulic pressure cylinders arranged at right angles to each other on said. frame, hydraulic pistons working in said cylinders, said pistons being connected with said support and` tool and adapted to press thelast carried by the support against the tool and to. move said tool relatively to said last for the purpose of ystripping the shoe from the last, and an overflow pipe connected to the pressure cylinder of the piston which moves the de-lasting tool and adapted to limit the movement of said piston.

9. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted, a de-lasting tool carried by said frame and movable relatively to said last, two hydraulic pressure cylinders arranged at right angles to each other on said frame, hydraulic pistons Working in said cylinders, said pistons being connected with said support and tool and adapted to press the last carried .by the support against the tool and to move said tool relatively to said last for the purpose of stripping the shoe from the last, a liquid pump common to both cylinders, a sump for the liquid to be delivered to the pump, means connecting said pump With the sump and the cylinders respectively, and a reversing valve provided in connection with said means adapted to permit, in one position, the pressure medium to run back without exerting any action into the sump and in the other position to cut off the path of return iiow and meansfor controlling said valve.

10. In a machine for de-lasting boots and shoes,

: in combination with the machine frame, a support for a last movably arranged on said frame and on Whichthe shoe to be de-lasted is mounted, a de--lasting tool carried by said frame and movable relatively' to said last, two hydraulic pres- Lv sure vcylinders arranged at right angles to each other on said frame, hydraulic pistons Working in said cylinders, said pistons being connected with said support and tool and adapted to press the last carried by the support against the tool 1,'. and to move said tool relatively to said last for the purpose of stripping the shoe from the last, a liquid pump common to both cylinders, a sump for the liquid to be delivered to the pump, means connecting said pump with the sump and the cylinders respectively, a reversing valve provided in connection with said means adapted to permit, in one position, the pressure medium to run back Without exerting any action into the sump and in the other position to cut off the path of return flow, and a safety valve located within the reversing valve adapted to automatically open When the pressure of the pressure medium exceeds a predetermined maximum value, thereby permitting said pressure medium to flovv back directly to the sump and means for controlling said reversing valve.

l1. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support. for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted, a. de-lasting tool carried by said frame and movable relatively to said last, hydraulic means for pressing the last against the de-lasting tool, and hydraulic means for moving said tool relatively to said last for the purpose of stripping the shoe 'from the last, said de-lasting tool comprising a substantially cylindrical member of yielding material.

12. 'In a machine for de-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be cle-lasted is mounted, a de-lasting tool carried by said frame and movable relatively to said last, hydraulic means for pressing the last against the de-lasting tool, and

hydraulic means for moving said tool relatively to said last for the purpose of stripping the shoe from the last, said de-lasting tool comprising a substantially cylindrical member of yielding material and having its external surface conformed to the shape of the heel portion of the shoe to be de-lasted.

13. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted, a de-lasting tool carried by said frame and movable relatively to said last, hydraulic means for pressing the last against the de-lasting tool, and hydraulic means for moving said tool relatively to said last for the purpose of stripping the shoe from the last, said de-lasting tool comprising a substantially cylindrical member of yielding material and being provided on its external surface With shaped channels conformed to the shape of the heel portion of the shoe to be de-lasted.

14. In a machine for de-lasting boots and shoes, in combination with the machine frame, a support for a last movably arranged on said frame and on which the shoe to be de-lasted is mounted, a delasting tool carried by said frame and movable relatively to said last, hydraulic means for pressing the last against the de-lasting tool and hydraulic means for moving said tool relatively to said last for the purpose of stripping the shoe from they last, said de-lasting tool comprising a substantially cylindrical member of yielding material and being provided on its external surface With a plurality of diierently shaped channels conforming to the shape of the heel portions of the different shoes to be de-lasted, and means for adjusting said tool so that the said channels can be selectively used as surfaces for pressing the shoe against the last.

15. A machine for de-lasting boots and shoes comprising a support for a last movably arranged and on which the shoe to be de-lasted is mounted, a de-lasting tool movable relative to said support and the last to be carried thereby, and hydraulic means for moving said support and the de-lasting tool so that the last with the shoe thereon is pressed against the tool and the tool is moved relative to the last to strip the shoe from the last.

1S. A machine for de-lasting boots and shoes comprising a frame, a support for a last movably mounted on the frame and on which the shoe to be de-lasted is mounted, a de-lasting tool movably mounted on the frame relative to said support and the last to be carried thereby, and hydraulic means mounted on the frame for moving said support and the de-lasting tool so that the last with the shoe thereon is pressed against the tool and the tool is moved relative to the last to strip the shoe from the last.

1'7. A machine according to claim 15, in which the hydraulic means includes mechanism to exert forces for the de-lasting operation which adjust themselves automatically in a denite relationship so that the shoe will be forced against the de-lasting tool in a definite ratio to the force required to de-last the shoe from the last.

18. A machine according to claim 16, in which the hydraulic means includes mechanism to exert forces for the de-lasting operation which adjust themselves automatically in a definite relationship so that the shoe will be forced against the de-lasting tool in a denite ratio to the force required to de-last the shoe from the last.

MAX GRNE. 

